1. Field of the Invention
The present invention relates to a washing machine, and more particularly, to a washing machine which uses liquid detergent.
2. Discussion of the Related Art
Generally, a washing machine performs the function of separating dirt from clothes, bedding and so on (hereinafter, referred to as ‘laundry’) using water, detergent and a mechanical operation. Recently, a washing machine performs even the function of drying wet laundry using a dry hot air heated by a heater and a mechanical operation.
Recently, the studies of a washing machine using liquid detergent in place of powder detergent or along with powder detergent have been going on. In such a washing machine that uses liquid detergent, if the washing machine is not used for a long time, the liquid detergent left in pipelines is easy to be solidified due to the contact with air or the like. Such a solidification of liquid detergent causes clogging of pipelines, thereby causing the washing machine to malfunction and lowering consumers' reliability on the product. Also, if liquid detergent remains in a pump that feeds liquid detergent, solidified liquid detergent may damage the pump.
Besides, the liquid detergent stored in a liquid detergent storage part is also solidified when exposed to air for a long time. In this case, it becomes difficult to smoothly supply liquid detergent required for washing.